Positive-working photosensitive resin precursor composition

ABSTRACT

The present invention relates to a positive-working photosensitive resin precursor composition which is characterized in that it contains (a) polymer in which the chief component comprises structural units of the kind where the bonding between structural units is represented by general formula (1) and (b) photoacid generator, and it can form a pattern by light irradiation and subsequent developing, and the total carboxyl groups contained in said polymer is from 0.02 to 2.0 mmol/g, and it provides a photosensitive resin composition of high sensitivity which can be developed by alkali.  
                 
 
     (R 1  is an organic group of valency from 3 to 8 having at least 2 carbon atoms, R 2  is an organic group of valency from 2 to 6 having at least 2 carbon atoms, R 3  is hydrogen or an organic group with from 1 to 20 carbons. n is an integer of value from 3 to 100,000, m is 1 or 2, p and q are integers of value from 0 to 4 and p+q&gt;0.)

TECHNICAL FIELD

[0001] The present invention relates to a photosensitive resincomposition which can be used for the interlayer dielectrics ofsemiconductor devices and for buffer coat films, α-ray shielding filmsand the like, and which can form patterns by exposing to actinicradiation and dissolving away the exposed regions with aqueous alkalisolution.

TECHNICAL BACKGROUND

[0002] Heat-resistant resins such as polyimides are employed in thesemiconductor field to form interlayer dielectrics, buffer coat films,α-ray shielding films and the like. In using a polyimide in suchapplications, patterning of the polyimide film is necessary for thepurpose of through hole formation and the like. For example, a solutionof the polyamic acid, which is the polyimide precursor, is applied tothe substrate, and then converted to the polyimide by heat treatment,after which a positive photoresist relief pattern is formed on thepolyimide film and, with this as a mask, patterning is carried out byselective etching of the polyimide film by means of a hydrazine etchingagent. However, this method has the problem that, as well as the processbeing complex since it includes the photoresist application and removalsteps, etc, dimensional accuracy is lowered because of side etching. Forsuch reasons, photosensitive resin compositions have been Investigatedwhich are heat-resistant resins, or precursors which can be converted toheat-resistant resins by means of a heat treatment or the like, andwhich themselves can undergo pattern processing.

[0003] For photosensitive resin compositions to have a pattern accuracyenabling them to be employed in passivation layer pattern formation, amethod has been investigated whereby first of all patterning and curingof the photosensitive resin precursor composition is carried out on thepassivation layer prior to pattern formation and then, with this patternas a mask, dry etching of the underlying passivation layer is carriedout (the one mask process). In accordance with this method, it ispossible to shorten the process required in passivation layer patternformation, leading to a reduction in costs.

[0004] When using a photosensitive resin composition, normallyapplication and drying on the substrate are performed in the solutionstate, and irradiation with active light rays is performed through amask. As negative-working photosensitive resin precursor compositionswhere the exposed regions are left following the developing, there areknown compositions where a carbon-carbon double bond which is dimerizedor polymerized by actinic radiation and an amino group or quaternizedsalt thereof are added to a polyamic acid (JP-B-59-52822), compositionswhere an acrylamide is added to the polyamic acid (JP-A-3-170555) andcompositions where a polyimide precursor with a carbon-carbon doublebond, a specified oxime compound and a sensitising agent areincorporated (JP-A-61-118423). However, there is the problem thatchanging over from a conventional non photosensitive resin compositionpatterning process using a positive-working photoresist to a processusing a negative-working photosensitive resin composition requires achange in the exposure device mask and a change in the developingequipment. Furthermore, these negative-working photosensitive resincompositions employ organic solvents in the developing, but from thepoint of view of preventing environmental pollution and improving theworking environment, a photosensitive material which can be developedwith an aqueous developer liquid instead of an organic developer liquidis desirable. For these reasons, alkali-developable positive-workingphotosensitive resin compositions are being investigated.

[0005] As known examples of positive-working photosensitive resincompositions where the exposed regions are dissolved away by developingwith an aqueous alkali solution, there are the polyimide precursorswhere o-nitrobenzyl groups have been introduced by ester bonds(JP-A-60-37550), the composition where an o-quinone diazide compound ismixed Into a polyamic acid ester (JP-A-2-181149), the composition wherean o-quinone diazide compound is mixed with a polyamic acid or polyamicacid ester which has a phenolic hydroxyl group (JP-A-3-115461), thecomposition where an o-quinone diazide compound is mixed with apolyimide which has a phenolic hydroxyl group (JP-3-177455), and thecomposition where an o-quinone diazide compound is mixed with apolyhydroxyamide (JP-B-1-46862).

[0006] However, the polyimide precursors with o-nitrobenzyl groupsintroduced by means of ester bonds have the problem that the sensitisingwavelengths are mainly below 300 nm and the sensitivity is low. In thecase where an o-quinone diazide compound is mixed into the polyamic acidester, the rate of dissolution by the alkali developer is low, so thesensitivity is low and the developing time is lengthy. In the case wherean o-quinone diazide compound is added to a polyamic acid with aphenolic hydroxyl group, the solubility in the alkali developer is toogreat, so there is the problem that only dilute developer liquid can beemployed and, since the unexposed regions are swollen by the developerliquid, fine patterning is difficult. Where an O-quinone diazidecompound is mixed with a polyamic acid compound or polyimide with aphenolic hydroxyl group, the dissolution rate in the alkali developer isimproved but there is the problem that further adjustment of thedissolution rate is difficult. Where an o-quinone diazide compound ismixed with a polyhydroxyamide, the dissolution rate in the alkalideveloper is improved but there is the problem that change to thepolymer composition is required for further adjustment in thedissolution rate. The present invention has been made in view of thesevarious problems of the prior art, and it has as its objective to offera photosensitive resin composition where adjustment of the dissolutiontime in the aqueous alkali solution is possible and, furthermore, wherethe polymer transparency is high at the exposure wavelengths and whichhas high sensitivity.

DISCLOSURE OF THE INVENTION

[0007] The present invention is a positive-working photosensitive resincomposition which is characterized in that it contains (a) polymer inwhich the chief component comprises structural units of the kind wherethe bonding between structural units is represented by general formula(1) and (b) photoacid generator, and which can form a pattern by lightirradiation and subsequent developing, and the total carboxyl groupscontained in 1 g of said polymer is from 0.02 to 2.0 mmol

[0008] (R¹ is an organic group of valency from 3 to 8 having at least 2carbon atoms, R² is an organic group of valency from 2 to 6 having atleast 2 carbon atoms, R³ is hydrogen or an organic group with from 1 to20 carbons but it is not all hydrogen. n is an integer of value from 3to 100,000, m is 1 or 2, p and q are integers of value from 0 to 4 andp+q>0.)

[0009] Optimum Form for Practising the Invention

[0010] In the present invention, the polymer represented by generalformula (1) is preferably one which can form a polymer with imide rings,oxazole rings or other cyclic structures by heating or by means of asuitable catalyst. By forming cyclic structures, the heat resistance andsolvent resistance are markedly enhanced. The polymer in whichstructural units represented by aforesaid general formula (1) are thechief component preferably has hydroxyl groups. In such circumstances,because of the presence of the hydroxyl groups, the solubility inaqueous alkali solution is better than that of a polyamic acid whichdoes not have hydroxyl groups. In particular, from amongst hydroxylgroups, phenolic hydroxyl groups are preferred in terms of theirsolubility in aqueous alkali solution.

[0011] The residual group which constitutes R¹ in general formula (1)denotes an acid structural component, and this acid component ispreferably a C₂ to C₆₀ trivalent to octavalent group containing anaromatic ring and having from one to four hydroxyl groups. Where R¹ doesnot contain hydroxyl groups, desirably the R² component contains fromone to four hydroxyl groups. An example is shown by general formula (6).

[0012] (R⁷ and R⁸ represent C₁ to C₂₀ organic groups of valency 3 or 4,R⁸ represents a hydroxyl group-containing C₃ to C₂₀ organic group ofvalency from 3 to 6, and R¹⁰ and R¹¹ are each hydrogen or a C₁ to C₁₀monovalent organic group. R¹⁰ and R¹¹ are not all hydrogen atoms, norare they all C₁ to C₁₀ monovalent organic groups. r and t represent theintegers 1 or 2, and s denotes an integer of value from 1 to 4.)

[0013] Furthermore, the hydroxyl groups are preferably in a positionadjacent to an amide bond. As examples thereof, there are structures ofthe kind shown in (10) below, but the present invention is notrestricted to these.

[0014] (R is a hydrogen atom or a C₁ to C₂₀ monovalent organic group)

[0015] Furthermore, for the residual groups containing R¹, it is alsopossible to employ tetracarboxylic acids, tricarboxylic acids anddicarboxylic acids which do not contain hydroxyl groups. As examplesthereof, there are aromatic tetracarboxylic acids such as pyromelliticacid, benzophenonetetracarboxylic acid, biphenyltetracarboxylic acid,diphenyl ether tetracarboxylic acid and diphenyl sulphonetetracarboxylic acid, and the diesters thereof where two of the carboxylgroups are in the methyl or ethyl group form; aliphatic tetracarboxylicacids such as butane tetracarboxylic acid and cyclopentanetetracarboxylic acid, and the diesters thereof where two of the carboxylgroups are in the methyl or ethyl group form; and aromatic tricarboxylicacids such as trimellitic acid, trimesic acid, naphthalene tricarboxylicacid and the like.

[0016] The residual group which constitutes R² in general formula (1)denotes a diamine structural component Preferred examples of R² arethose with an aromatic ring, from the point of view of the heatresistance of the polymer obtained, and also having from one to fourhydroxyl groups. Where R² does not have hydroxyl groups, it is desirablethat the R¹ component contain from one to four hydroxyl groups.Furthermore, the hydroxyl groups are preferably positioned adjacent toan amide bond.

[0017] As specific examples, there are compounds such asbis(aminohydroxyphenyl)hexafluoropropane, diaminodihydroxypyrimidine,diaminodihydroxypyridine, hydroxydiaminopyrimidine, diaminophenol anddihydroxybenzene, and those with the following structures.

[0018] (i is an integer in the range 1 to 4, j and k are integers in therange 0 to 4, and j+k is at least 1.)

[0019] Amongst these R² components, as further preferred examples therecan be cited the compounds with the structures shown by general formulae(7), (8) and (9). Of these, specific examples of further preferredstructures are exemplified by general formulae (11), (12) and (13).

[0020] (R¹² and R¹⁴ represent hydroxyl group-containing C₂ to C₂₀organic groups of valency 3 or 4, and R¹³ represents a C₂ to C₃₀divalent organic group. u and v represent the integers 1 or 2.)

[0021] (R¹⁵ and R¹⁷ represent C₂ to C₃₀ divalent organic groups, and R¹⁶represents a hydroxyl group-containing C₂ to C₂₀ organic group ofvalency 3 to 6. w represents an integer in the range 1 to 4.)

[0022] (R¹⁸ represents a C₂ to C₃₀ divalent organic group, and R¹⁹represents a hydroxyl group-containing C₂ to C₂₀ organic group ofvalency 3 to 6. x represents an integer in the range 1 to 4.)

[0023] Furthermore, it is also possible to use a diamine which does notcontain a hydroxyl group for the residual group containing R² in generalformula (1). As examples thereof, there are phenylenediamine,diaminodiphenyl ether, aminophenoxybenzene, diaminodiphenylmethane,diaminodiphenylsulphone, bis(trifluoromethyl)benzidine,bis(aminophenoxyphenyl)propane, bis(aminophenoxyphenyl)sulphone orcompounds comprising these aromatic rings with alkyl group and/orhalogen atom substituents, and aliphatic cyclohexyldiamine, methylenebiscyclohexylamine and the like. These diamine compounds can be used ontheir own or they can be used in combinations of two or more types. Itis preferred that they be used as no more than 40 molt of the diaminecomponent. If more than 40 molt is copolymerized then the heatresistance of the polymer obtained is lowered.

[0024] With the objective of improving the adhesion to the substrate, itis also possible to use a diamine compound with a siloxane structurewithin a range such that the heat resistance is not lowered. As examplesof diamines with a siloxane structure, there may be usedbis(3-aminopropyl)tetramethyldisiloxane,bis(3-aminopropyl)tetraphenyldisiloxane,bis(4-aminophenyl)tetramethyldisiloxane and the like.

[0025] R³ in general formula (1) represents hydrogen or a C₁ to C₂₀organic group. If the number of carbons in R³ exceeds 20 then thesolubility in aqueous alkali is lost. In terms of the stability of thephotosensitive resin solution obtained, R³ is preferably an organicgroup, but hydrogen is preferred in terms of the solubility in aqueousalkali. In other words, it is not desirable that R³ all be hydrogen orthat it all be an organic group. By adjusting the proportion of R³ whichcomprises hydrogen or which comprises an organic group, the dissolutionrate in aqueous alkali solution may be varied, so by such adjustment itis possible to obtain a photosensitive resin composition with a suitabledissolution rate. Thus, the carboxyl group content of the polymer ispreferably from 0.02 mmol to 2.0 mmol per 1 g of polymer. Morepreferably, it is from 0.05 mmol to 1.5 mmol. If there is less than 0.05mmol, then the solubility in the developer liquid is too low, while ifthere is more than 2.0 mmol then it is not possible to realise adifference in dissolution rate between the exposed and unexposed regionsm represents 1 or 2, and p and q are each integers in the range 0 to 4,with p+q>0. If p is 5 or more, then the properties of the heat-resistantresin film obtained are impaired.

[0026] Again, it is possible to control the amount of residual carboxylgroups by imidization of some of the carboxyl groups. As the method ofimidization, any known imidization method can be used. The proportion ofthe imidization at this time is preferably from 1% to 50%. If thepercentage imidization exceeds 50%, then the absorption by the polymerof the actinic radiation used for exposure is increased and thesensitivity decreased.

[0027] The polymer represented by general formula (1) is preferably astransparent as possible in terms of the actinic radiation used forexposure. Hence, the absorbance of the polymer at 365 nm is preferablyno more than 0-1 per 1 μm of film thickness. More preferably, it is nomore than 0.08. If it is more than 0.1, then the sensitivity in terms ofexposure to 365 nm actinic radiation is lowered.

[0028] The positive-working photosensitive resin composition of thepresent invention may only comprise structural units represented bygeneral formula (1), or it may comprise a copolymer with otherstructural units or a blend. In such circumstances, the content of thestructural units represented by general formula (1) is preferably atleast 90 molt. The type and amount of structural units employed forcopolymerisation or blending are preferably selected from within a rangesuch that the heat resistance of the polyimide polymer obtained by thefinal heat treatment is not impaired.

[0029] Generally speaking, the polymer represented by general formula(1) can be obtained by treating the carboxyl groups in a polymerrepresented by general formula (2) by means of a compound represented bygeneral formula (3), (4) or (5).

[0030] (R¹ is 3-valent to 8-valent organic group with at least 2carbons, and R² is a 2-valent to 6-valent organic group with at leasttwo carbon atoms. n is an integer in the range 3 to 100,000, m is 1 or2, p and q are each integers in the range 0 to 4 and p+q>0.

[0031] The polymer chiefly comprising structural units represented bygeneral formula (2) in the present invention is synthesized by knownmethods. For example, it can be synthesized by the method of reacting atetracarboxylic dianhydride and a diamine compound at low temperature(C. E. Sroog et al, J. Polymer Science, Part A-3, 1373 (1965)).

[0032] In general formula (3), R⁴ and R⁵ represent a hydrogen atom or amonovalent organic group, nitrogen-containing organic group oroxygen-containing organic group with at least one carbon. R⁴ and R⁵ maybe the same or different. R⁶ represents a monovalent organic group withat least one carbon.

[0033] R⁴ in general formula (3) represents a hydrogen atom or amonovalent organic group with at least one carbon, R⁵ represents ahydrogen atom or a monovalent organic group, nitrogen-containing organicgroup or oxygen-containing organic group with at least one carbon, R⁶ ingeneral formula (3) or in general formula (4) represents a monovalentorganic group with at least one carbon and R⁷ represents a divalentorganic group, nitrogen-containing organic group or oxygen-containingorganic group with at least one carbon. Specifically, in the case of thecompounds represented by general formula (3), examples areN,N-dimethylformamide dimethyl acetal, N,N-dimethylformamide diethylacetal, N,N-dimethylformamide dipropyl acetal, N,N-dimethylformamidedibutyl acetal, N,N-dimethylformamide dibenzyl acetal,N,N-dimethylformamide bis[2-(trimethylsilyl)ethyl] acetal,N,N-dimethylacetamide diethyl acetal, trimethyl orthoformate, triethylorthoformate, trimethyl orthoacetate, triethyl orthoacetate, trimethylorthobutyrate, triethyl orthobutyrate, trimethyl orthobenzoate, triethylorthobenzoate, 1,3-dimethylimidazolidinone dialkyl acetal, ethylenecarbonate dialkyl acetal, propylene carbonate dialkyl acetal and thelike, with N,N-dimethylformamide dimethyl acetal, N,N-dimethylformamidediethyl acetal, N,N-dimethylformamide dipropyl acetal,N,N-dimethylformamide dibutyl acetal and N,N-dimethylformamide dibenzylacetal preferred.

[0034] As examples of the compounds represented by general formula (4),R⁷ represents a divalent organic group which forms a ring. Preferredexamples of the compounds represented by general formula (4) areN-methylpyrrolidone dimethyl acetal, N-methylpyrrolidone diethyl acetal,N-methylpyrrolidone dipropyl acetal, N-methylpyrrolidone dibutyl acetal,γ-butyrolactone dimethyl acetal, γ-butyrolactone diethyl acetal and thelike. As specific examples of the compounds represented by generalformula (5), there are methyl vinyl ether, ethyl vinyl ether, n-propylvinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, isobutyl vinylether, tert-butyl vinyl ether, cyclohexyl vinyl ether and the like, butthere is no restriction to these. Preferably, tert-butyl vinyl ether,cyclohexyl vinyl ether and isopropyl vinyl ether are used.

[0035] At the time of the esterification treatment of the polymerrepresented by general formula (2) by means of general formula (3),general formula (4) or general formula (5), imidization may also takeplace as a side reaction but the proportion of imidization in terms ofthe esterification reaction can be suppressed by selection of thereaction conditions, namely by selection of the reaction solvent and thereaction temperature, etc.

[0036] As the reaction solvent, there is preferably usedN-methyl-2-pyrrolidone (NMP), N,N-dimethylformamide,N,N-dimethylacetamide, dimethylsulphoxide, 1,3-dimethylimidazolidinone,hexamethylphosphoramide, γ-butyrolactone or other such non-protic polarsolvent, with N-methyl-2-pyrrolidone, N,N-dimethylformamide andN,N-dimethylacetamide more preferred. As solvents other than these,there can be used, In total or in part, ketone solvents such as acetoneor methyl ethyl ketone, alcohol solvents such as methanol or ethanol, orester solvents such as propylene glycol monomethyl ether acetate, ethyllactate or the like. The esterification reaction temperature lies in therange from 0° C. to 150° C., preferably 20° C. to 100° C. and morepreferably 30° C. to 80° C. If the reaction temperature is less than 0°C. then the time for the reaction to reach completion is prolonged andso this becomes impractical. Furthermore, when the reaction temperatureexceeds 150° C., problems readily arise such as the extent ofimidization increasing, the polymer transparency falling and a gelcomponent being produced. In the treatment by means of a compoundrepresented by general formulae (3) or (4) it is possible, for thepurpose of accelerating the reaction, to employ from 0.01 to 10 molt ofan acid such as trifluoroacetic acid, p-toluenesulphonic acid ormethanesulphonic acid, or of a base such as triethylamine, pyridine orthe like.

[0037] At the time of the reaction between the polymer represented bygeneral formula (2) and a compound represented by general formula (3),(4) or (5), there may also be added an acid compound as a catalyst foraccelerating the reaction. With regard to the amount of such acidcompound added, for the purposes of selectively accelerating thereaction there can be used from 0.01 to 10 molt in terms of the carboxylgroups. As specific examples of the acid catalyst there are hydrochloricacid, sulphuric acid, nitric acid, phosphoric acid, oxalic acid and thelike, but there is no restriction to these. Preferably, there is usedhigh pKa value phosphoric acid or oxalic acid. This is thought to bebecause the higher the pKa value of the acid catalyst the greater thenucleophilic character of the counter anion produced, and cationicpolymerisation is suppressed.

[0038] The amount of the compound represented by general formula (3),(4) or (5) added can be determined from the concentration of thecarboxyl groups in the polymer represented by general formula (2).

[0039] The compounds represented by general formulae (3), (4) and (5)may be used on their own or they may be used as mixtures of a pluralitythereof.

[0040] As an alternative thereto for esterification of the carboxylgroups, it is possible to jointly use the method of converting thecarboxylic acid to the silver salt and subjecting this to the action ofan alkyl halide, the method of using diazomethane, or the reaction basedon dialkyl sulphate, etc.

[0041] The preferred reaction solvent is N-methyl-2-pyrrolidone (NMP),N,N-dimethylformamide, N,N-dimethylacetamide, dimethylsulphoxide,1.3-dimethylimidazolidinone, hexamethylphosphoramide, γ-butyrolactone orother such non-protic polar solvent, with N-methyl-2-pyrrolidone,N,N-dimethylformamide and N,N-dimethylacetamide further preferred. Thereaction temperature lies in the range from −10° C. to 150° C.,preferably 0° C. to 80° C. and more preferably 10° C. to 60° C. If thereaction temperature is below −10° C., the time for the reaction toreach completion is prolonged and so it becomes impractical. Again, ifthe reaction temperature exceeds 150° C., problems arise due toreactions such as imidization, a reduction in the polymer transparency,the formation of a gel component and a lowering of the cured filmproperties.

[0042] Treatment of the polymer represented by general formula (2) bythe compounds represented by general formulae (3), (4) or (5) is carriedout by mixing and stirring general formula (3), (4) or (5) and,optionally, an acid catalyst, with a solution of general formula (2)dissolved in an organic solvent. In the case where the solvent used atthe time of the synthesis of the polymer represented by general formula(2) and the solvent used when treating the polymer with general formula(3) and the acid catalyst compound are the same, then said treatment canbe carried out by mixing and stirring the compound of general formula(3), (4) or (5) with the solution obtained following polymerisation.

[0043] As examples of the photoacid generator employed in the presentinvention, there are compounds which are decomposed and generate acid byirradiation such as diazonium salts, diazoquinone sulphonamides,diazoquinone sulphonic acid esters, diazoquinone sulphonates,nitrobenzyl esters, onium salts, halides, halogenated isocyanates,triazine halides, bisarylsulphonyldiazomethanes, disulphones and thelike. In particular, o-quinone diazide compounds are preferred sincethey have the effect of suppressing the water solubility of theunexposed regions. Such compounds include1,2-benzoquinone-2-azido-4-sulphonate ester or sulphonamide,1,2-naphthoquinone-2-diazido-5-sulphonate ester or sulphonamide,1,2-naphthoquinone-2-diazido-4-sulphonate ester or sulphonamide, and thelike. These can be obtained for example by a condensation reactionbetween an o-quinonediazide sulphonyl chloride such as1,2-benzoquinone-2-azido-4-sulphonyl chloride,1,2-naphthoquinone-2-diazido-5-sulphonyl chloride or1,2-naphthoquinone-2-diazido-4-sulphonyl chloride, and a polyhydroxycompound or polyamine compound in the presence of a dehydrochlorinationcatalyst.

[0044] As examples of the polyhydroxy compound, there are hydroquinone,resorcinol, pyrogallol, bisphenol A, bis(4-hydroxyphenyl)methane,2,2-bis(4-hydroxyphenyl)hexafluoropropane, 2,3,4-trihydroxybenzophenone,2,3,4,4′-tetrahydroxybenzophenone, 2,2′,4,4′-tetrahydroxybenzophenone,tris(4-hydroxyphenyl)methane, 1,1,1-tris(4-hydroxyphenyl)ethane,1-[1-(4-hydroxyphenyl)isopropyl]-4-[1,1-bis(4-hydroxyphenyl)ethyl]benzene,methyl gallate, ethyl gallate and the like.

[0045] As examples of the polyamine compounds there are1,4-phenylenediamine, 1,3-phenylenediamine, 4,4′-diaminodiphenyl ether,4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylsulphone,4,4′-diaminodiphenylsulphide and the like.

[0046] As polyhydroxypolyamine compounds, there are2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane,3,3-dihydroxybenzidine and the like.

[0047] Preferably from 5 to 100 parts by weight, and more preferablyfrom 10 to 40 parts by weight, of the o-quinone diazide compound ismixed per 100 parts by weight of the polymer represented by generalformula (1). With less than 5 parts by weight, insufficient sensitivityis obtained, while with more than 100 parts by weight there is thepossibility that the heat resistance of the resin composition will belowered.

[0048] The positive-working photosensitive resin composition of thepresent invention is preferably employed in the solution state bydissolving the polymer represented by general formula (1), which isobtained by treating polymer represented by general formula (2) with acompound represented by general formula (3), (4) or (5), in a solventalong with the photoacid generator. As the solvent, non-protic polarsolvents such as N-methyl-2-pyrrolidone, N,N-dimethylformamide,N,N-dimethylacetamide, dimethylsulphoxide, 1,3-dimethylimidazolidinone,hexamethylphosphoramide and γ-butyrolactone may be used on their own, orin combinations of two or more thereof, but other solvents can also beused providing that they will dissolve the polymer represented bygeneral formula (1) and the photosensitizer.

[0049] Again, where required, with the objective of enhancing theapplication properties between the photosensitive precursor compositionand the substrate, there may also be mixed therein surfactants, esterssuch as ethyl lactate and propylene glycol monomethyl ether acetate,alcohols such as ethanol, ketones such as cyclohexanone and methylisobutyl ketone, and ethers such as tetrahydrofuran and dioxane Again,it is possible to add inorganic particles such as silicon dioxide andtitanium dioxide, or polyimide powder, etc.

[0050] Furthermore, in order to enhance the adhesion to an underlyingsubstrate such as a silicon wafer, it is possible to add from 0.5 to 10parts by weight of a silane coupling agent, titanium chelating agent orthe like to the photosensitive resin composition varnish, or theunderlying substrate may be pretreated with such a chemical.

[0051] When added to the varnish, from 0.5 to 10 parts by weight of thesilane coupling agent, such as methyl methacryloxydimethoxysilane or3-aminopropyltrimethoxysilane, or of the titanium chelating agent oraluminium chelating agent is added in terms of the polymer in thevarnish.

[0052] When treating the substrate, a solution obtained by dissolving0.5 to 20 parts by weight of the aforesaid coupling agent in a solventsuch as isopropanol, ethanol, methanol, water, tetrahydrofuran,propylene glycol monomethyl ether acetate, propylene glycol monomethylether, ethyl lactate, diethyl adipate or the like is used to treat thesurface by spin coating, immersion, spray application or vapourtreatment, etc. Depending on the circumstances, by subsequentapplication of temperature in the range 50° C. to 300° C., reactionbetween the substrate and the coupling agent is promoted.

[0053] Next, explanation is provided of the method of forming aheat-resistant resin pattern using the photosensitive resin compositionof the present invention.

[0054] The photosensitive resin composition of the present invention isapplied onto the substrate. As the substrate, there may be used asilicon wafer, a ceramic, gallium arsenide or the like, but there is norestriction to these. The application method may be rotary applicationusing a spinner, spray application, roll coating or the like.Furthermore, the applied film thickness will differ with the applicationmeans, the solids content of the composition and the viscosity, etc, butnormally application is performed such that the film thickness afterdrying is from 0.1 to 150 μm.

[0055] Next, the photosensitive resin composition coating is obtained bydrying the substrate on which the photosensitive resin composition hasbeen applied. The drying is preferably carried out using an oven, hotplate or infrared radiation, etc, for from 1 minute to several hourswithin the range 50° C. to 150° C.

[0056] Subsequently, this coating is irradiated with actinic radiationthrough a mask with the desired pattern, and exposure effected. Examplesof the actinic radiation employed for the exposure are ultravioletlight, visible light, an electron beam, X-rays and the like, but it ispreferred in the present invention that there be used the mercury lampi-line (365 nm), h-line (405 nm) or g-line (436 nm).

[0057] To form the heat-resistant resin pattern, the exposed regions areeliminated using a developer liquid following the exposure. Preferredexamples of the developer liquid are aqueous tetramethylammoniumsolutions, and aqueous solutions of compounds which exhibit alkalinitysuch as diethanolamine, diethylaminoethanol, sodium hydroxide, potassiumhydroxide, sodium carbonate, potassium carbonate, triethylamine,diethylamine, methylamine, dimethylamine, dimethylaminoethyl acetate,dimethylaminoethanol, dimethylaminoethyl methacrylate, cyclohexylamine,ethylenediamine, hexamethylenediamine and the like. Further, dependingon the circumstances, there may be added to such aqueous alkalisolutions a polar solvent such as N-methyl-2-pyrrolidone,N,N-dimethylformamide, N,N-dimethylacetamide, dimethylsulphoxide,γ-butyrolactone or dimethylacrylamide, an alcohol such as methanol,ethanol or isopropanol, an ester such as ethyl lactate or propyleneglycol monomethyl ether acetate, a ketone such as cyclopentanone,cyclohexanone, isobutyl ketone or methyl isobutyl ketone, or acombination of more than one such solvent. After developing, a rinsingtreatment is carried out with water. The rinsing treatment may also becarried out with the addition, to the water, of an alcohol such asethanol or isopropyl alcohol, ester such as ethyl lactate or propyleneglycol monomethyl ether acetate, or carbon dioxide, hydrochloric acid,acetic acid or other such acid.

[0058] Following the developing, by application of a temperature of from200° C. to 500° C. conversion is effected to the heat-resistant resincoating. This heat treatment is carried out for from 5 minutes to 5hours either by selection of temperatures and raising the temperature instepwise fashion, or by selecting a temperature range and continuouslyraising the temperature. As an example, heat treatment is carried outfor 30-minute periods at 130° C., 200° C. and 350° C. Alternatively,there is the method of linearly increasing the temperature over twohours from room temperature to 400° C.

[0059] The heat-resistant resin coating formed by means of thephotosensitive resin composition of the present invention may be used inapplications such as semiconductor passivation layers, semiconductordevice protective films and the interlayer dielectrics of multilayerinterconnects for high density mounting, etc.

EXAMPLES

[0060] Below, in order to explain the present invention in more detail,examples are provided, but the invention is not to be restricted tothese examples.

[0061] Methods of Measuring the Properties

[0062] Measurement of Film Thickness

[0063] Using a Lambda-Ace STM-602 manufactured by the Dainippon ScreenManufacturing Co., measurements were carried out at a refractive indexof 1.64. In this way, taking the film thickness prior to development asT1 and the film thickness of the unexposed regions after development asT2, if T2/T1×100 was 70% or less, or if the extent of film loss in thedevelopment was 2 μm or more, then the level of film loss by thedeveloping was large, which is undesirable. More preferably, T2/T1×100was at least 80%.

[0064] Furthermore, at the same time, the exposure level required forall the film to be dissolved by the developer was measured. Where thisvalue was greater that 500 mJ/cm², the sensitivity was low and so thisIs undesirable.

[0065] Measurement of the Light Absorbance

[0066] The polymer solution is coated onto a 5 cm×5 cm glass base plateof 1.2 mm thickness (#7059, manufactured by Matsunami Glass), andpre-baked for 3 minutes at 120° C. Using a Shimadzu Corporation UV-240,and with an identical glass plate which had not been coated with polymersolution as a reference, the absorbance of the coated film at 365 nm wasmeasured, and by dividing by the actual film thickness the absorbanceper 1 μm of film thickness was determined.

[0067] Measurement of the Percentage-Imidization

[0068] The polymer solution was coated onto a 4-inch silicon wafer togive a film thickness following prebaking of about 7 μm, and thenprebaking was carried out for 3 minutes at 120° C. Firstly, backgroundmeasurement was carried out using as a reference a 4-inch silicon wafer,on which no polymer solution had been applied, set on the hot plate.Next, the infrared absorption spectrum of the film was measured using anFT-720 manufactured by Horiba Ltd. Subsequently, using an inert oven,INH-21CD made by the Koyo Lindberg Co., heat treatment was carried outfor 30 minutes at 200° C., after which the temperature was increased to₃₅₀° C. over 1 hour and heat treatment conducted for 1 hour at 350° C.,so that complete imidization was performed. The infrared absorptionspectrum of this sample was then measured, and the percentageimidization was determined from the ratio of the C-N stretchingvibration peak (13.80 cm⁻¹) due to the imide bonds before and after theimidization treatment.

[0069] That is to say, taking the peak value at 1380 cm⁻¹ prior to thetreatment at 350° C. as A, and that following the sample treatment at350° C. as B, the percentage imidization I is expressed by the followingrelation.

I=A/B×100

[0070] Quantitative Determination of the Carboxyl Groups in the Polymer

[0071] About 100 ml of the polymer solution was added dropwise to 5litres of pure water, and the polymer precipitated. This was dried underreduced pressure for 48 hours in a vacuum drier at 80° C. 0.5 g of thedry polymer was dissolved in 40 ml of N-methyl-2-pyrrolidone (NMP) and10 ml of methanol, and the content of the free carboxyl groups in thepolymer determined by titration with a 1/10 N methanol solution oftetrabutylammonium hydroxide using a model F702 manufactured by ShibataKagaku Kikai Kogyo. With regard to the carboxyl groups per 1 g ofpolymer, taking the amount of the 1/10 N tetrabutylammonium hydroxidesolution in methanol required for neutralization in this titration as xml, the molar quantity of tetrabutylammonium hydroxide required for theneutralization is x/10 mmol. Since this molar quantity is equal to theamount of carboxyl groups per 0.5 g of polymer, the carboxyl groups per1 g of polymer is obtained by dividing by 0.5. In other words, it is x/5(mmol).

[0072] Resolution

[0073] A prebaked film formed on a silicon wafer was exposed through amask having various widths When developing was carried out, the minimumwidth where the pattern in the exposed region completely dissolvedfollowing development was taken as the resolution. Thus, the narrowerthis width, the finer the pattern that can be obtained, and the betterthe assessed resolution.

[0074] Measurement of Residual Quantities of Sodium, Potassium and IronIons

[0075] A solution obtained by weighing out 2 g of dried sample anddissolving with 25 ml of NMP was measured using a Z8000 Zeerman AtomicAbsorption Spectrometer manufactured by Hitachi Ltd. The calibration ofconcentration was performed using solutions of standard concentrationsof the respective ions. If the amount of these metal ions is 10 ppm ormore, there is a fear of corrosion when used as a coating agent, so thiswill be a problem.

[0076] Measurement of the Residual Chlorine Ion Concentration

[0077] 100 mg of dried sample was weighed out and dispersed in 20 ml ofwater, then ultrasonics applied for 2 hours using an ultrasonic cleaningdevice (B20H manufactured by BRANAON) and the chlorine ions extracted.Using an Ion Meter N-8M manufactured by Horiba Ltd, the concentration ofchlorine ions was measured with a chlorine ion electrode (8002manufactured by Horiba Ltd). The calibration of the chlorine ionconcentration was carried out using calcium chloride aqueous solutionsof known concentration. If the chlorine ion concentration is 30 ppm orabove, then there is a fear of corrosion when used as a coating agent orthe like, so this is a problem.

Synthesis Example 1 Synthesis of an Acid Anhydride Containing HydroxylGroups

[0078] 18.3 g (0.05 mol) of2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (BAHF) and 34.2 g (0.3mol) of allyl glycidyl ether were dissolved in 100 g ofgamma-butyrolactone (GBL) under a current of dry nitrogen, and cooled to−15° C. To this, there was added dropwise 22.1 g (0.11 mol) oftrimellitic anhydride chloride dissolved in 50 g of GBL, in such a waythat the temperature of the reaction liquid did not exceed 0° C.Following the end of the dropwise addition, reaction was carried out for4 hours at 0° C.

[0079] The solution was concentrated using a rotary evaporator, pouredinto 1 litre of toluene and the anhydride obtained. This is shown below.The material obtained did not show a clear melting point up to 350° C.

Synthesis Example 2 Synthesis of Hydroxyl Group-Containing DiamineCompound (1)

[0080] 183 g (0.05 mol) of BAHF was dissolved in 100 ml of acetone and17.4 g (0.3 mol) of propylene oxide, and cooled to −15° C. A solution of20.4 g (0.11 mol) of 3-nitrobenzoyl chloride dissolved in 100 ml ofacetone was added dropwise thereto. Following the completion of thedropwise addition, reaction was carried out for 4 hours at −15° C.,after which the solution was returned to room temperature. It was thenconcentrated using a rotary evaporator and the solid obtainedrecrystallized using a solution of tetrahydrofuran and ethanol.

[0081] The solid collected from the recrystallization was dissolved in100 ml of ethanol and 300 ml of tetrahydrofuran, then 2 g of 5%palladium-carbon added and vigorous stirring carried out. Hydrogen wasintroduced into this with a balloon, and a reduction reaction carriedout at room temperature. After about 2 hours, when it was confirmed thatthe balloon did not deflate any more, the reaction was halted. Followingthe end of the reaction, filtering was performed and the palladiumcompound catalyst eliminated. By concentration using the rotaryevaporator, the diamine compound was obtained. This is shown below. Thesolid obtained was used for reaction as it was. When the melting pointwas measured using a Shimadzu Differential Scanning Calorimeter DSC-50at a heating rate of 10° C./min, it was found to be 318° C.

Synthesis Example 3 Synthesis of Hydroxyl Group-Containing Diamine (2)

[0082] 30.8 g (0.2 mol) of 2-amino-4-nitrophenol was dissolved in 200 mlof acetone and 60 g (0.68 mol) of propylene oxide, and cooled to −15° C.A solution of 22.4 g (0.11 mol) of isophthaloyl chloride in 200 ml ofacetone was slowly added dropwise thereto. Following the completion ofthe dropwise, addition, reaction was carried out for 4 hours at −15° C.Subsequently, the solution was returned to room temperature and theprecipitate produced was collected by filtering.

[0083] 30 g of the dried precipitate and 3 g of 5% palladium-carbon wereadded along with 400 ml of Methyl Cellosolve to a 500 ml autoclave.Pressure was applied with hydrogen so that the internal pressure was 8kgf/cm², and stirring carried out for 2 hours at 80° C. Subsequently,when the temperature of the solution had fallen to 50° C. or less, thepressure was released, then filtering carried out and the precipitateremoved. The filtrate was concentrated with a rotary evaporator and thesolid produced was collected. This was dried for 20 hours in a vacuumdrier at 50° C. The structure of this material is shown below.

Synthesis Example 4 Synthesis of Hydroxyl Group-Containing Diamine (3)

[0084] 15.4 g (0.1 mol) of 2-amino-4-nitrophenol was dissolved in 80 nmof acetone and 30 g (0.34 mol) of propylene oxide, and cooled to −15° C.A solution of 19.5 g (0.105 mol) of 3-nitrobenzoyl chloride in 80 ml ofacetone was slowly added dropwise thereto. Following the completion ofthe dropwise addition, reaction was carried out for 4 hours at −15° C.Subsequently, the solution was returned to room temperature and theprecipitate produced was collected by filtering.

[0085] 25 g of the dried solid and 2 g of 5% palladium-carbon were addedto a 500 ml autoclave along with 300 ml of Methyl Cellosolve.Thereafter, the target precipitate was obtained in the same way as inSynthesis Example 3. This was dried for 20 hours in a vacuum drier at50° C. The structure is shown below.

Synthesis Example 5 Synthesis of a Naphthoquinone Diazide Compound

[0086] 20.2 g (0.05 mol) of1,1,2-tri(3,5-dimethyl-4-hydroxyphenyl)propane and 40.3 g (0.15 mol) of5-naphthoquinonediazidesulphonyl chloride were dissolved in 400 g of1,4-dioxane under a current of dry nitrogen, and the solution heated to40° C. To this, there was added dropwise 15.2 g (0.15 mol) oftriethylamine mixed with 40 g of 1,4-dioxane, in such a way that theinternal temperature of the system did not rise above 45° C. Followingthe dropwise addition, stirring was carried out for 2 hours at 40° C.The by-product triethyiamine hydrochloride was filtered off, and thefiltrate poured into 3 litres of 1% hydrochloric acid. Subsequently, theprecipitate which had been deposited was collected by filtering. Thisprecipitate was washed twice with 10 litres of water, then dried for 20hours in a vacuum drier at 50° C., and the naphthoquinone diazidecompound obtained. The structure of the compound is shown below.

Example 1

[0087] 20.0 g (100 Nmol) of 4,4′-diaminodiphenyl ether was dissolved in350 g of N-methyl-2-pyrrolidone (NMP) in a 1-litre four-necked flaskunder a current of dry nitrogen. To this, there was added 71.4 g (100mmol) of the acid anhydride synthesized in Synthesis Example 1, alongwith 40 g of GBL, and reaction carried out for 1 hour at 20° c, followedby 4 hours reaction at 50° C. Furthermore, 23.8 d (200 mmol) ofN,N-dimethylformamide dimethyl acetal was added, and stirring carriedout for 5 hours at 50° C. A solution of partially esterified polymer wasobtained. The carboxyl content of 1 g of this polymer was 0.07 mmol, thepercentage imidization was 10% and the absorbance at 365 nm was 0.083per 1 μm.

[0088] 5.5 g of the quinone diazide compound 4NT-300 (the ester obtainedby the reaction of 3 mol of 1,2-naphthoquinone-2-diazido-5-sulphonylchloride with 1 mol of 2,3,4,4′-tetrahydroxybenzophenone: produced byToyo Gosei Kogyo K.K.) was added to 100 g of the solution obtained, anda photosensitive resin composition solution obtained.

[0089] This solution was applied onto a 6-inch silicon wafer, to give afilm thickness after prebaking of 7 μm, and then using a hot plate(SKW-636 manufactured by the Dainippon Screen Mfg. Co.), prebaking wascarried out for 3 minutes at 120° C. and a photosensitive heat-resistantresin precursor film obtained. Next, a reticule on which a pattern hadbeen cut was set in an exposure means (i-line stepper NSR-1755-i7Aproduced by the Nikon Corp.) and i-line exposure carried out atexposures ranging from 100 mJ/cm² to 800 mJ/cm² in 50 mJ/cm² intervals.Subsequently, 100 seconds immersion was carried out in NMD-3 (2.38%aqueous solution of tetramethylammonium hydroxide; produced by the TokyoOhka Kogyo Co.), and then washing with water performed for a further 20seconds, to form the pattern.

[0090] As shown in Table 1, the film thickness in the unexposed regionsfollowing developing was 5.6 μm, so that the film loss by the developingwas 1.4 μm. Furthermore, the minimum irradiation level at the time ofpattern formation was low, at 300 mJ/cm², and so the sensitivity wasgood. Moreover, when the pattern profile was observed by electronmicroscopy, there was good 5 μm line and space resolution.

Example 2

[0091] 24.2 g (40 mmol) of the hydroxyl group-containing diaminecompound (1) synthesized in Synthesis Example 2 was dissolved in 100 gof NMP In a 1-litre four-necked flask under a current of dry nitrogen,then 11.8 g (40 mmol) of 3,3′,4,4′-biphenyltetracarboxylic dianhydrideadded and stirring carried out for 3 hours at 80° C. Furthermore, 8.8 g(60 mmol) of N,N-dlmethylformamide diethyl acetal was added, stirringcarried out for 2 hours at 80° C., and a solution of partiallyesterified polymer obtained The carboxyl group content per 1 g of thispolymer was 0.55 mmol, the percentage imidization was 35% and theabsorbance at 365 nm was 0.066 per 1 μm.

[0092] 100 g of this polymer solution and 3.5 g of the quinone diazidecompound 4NT-300 used in Example 1 were mixed together and aphotosensitive resin composition solution obtained.

[0093] Evaluation was carried out in the same way as in Example 1,except that the developing time was 50 seconds. The results are shown inTable 1. The film thickness of the unexposed regions followingdeveloping was 5.8 μm, so the level of film loss due to the developingwas low, at 1.2 μm. Moreover, the light irradiation level at the time ofpattern formation was 250 mJ/cm², indicating high sensitivity.Furthermore, when the pattern profile was observed by electronmicroscopy, there was good 10 μm line resolution.

Example 3

[0094] Polymerization was carried out in the same way as in Example 1,except that the diamine composition was 18.3 g (50 mmol) of2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (BAHF), 8.0 g (40mmol) of 4,4′-diaminodiphenyl ether and 2.5 g (10 mmol) of1,3-bis(3-aminopropyl)tetramethyldisiloxane. The carboxyl group contentin 1 g of this polymer was 0.35 mmol, the percentage imidization was 144and the absorbance was 0.045 per 1 μm. 30 g of this polymer wasdissolved in 70 g of GBL, and by dissolving 6 g of the quinone diazidecompound 4NT-300 employed in Example 1 there was obtained thephotosensitive resin composition solution.

[0095] Evaluation was carried out in the same way as in Example 1. Theresults are shown in Table 1. The film thickness of the unexposedregions following developing was 6.0 μm and so the film loss due todeveloping was low, at 1.0 μm. Moreover, the light irradiation level atthe time of pattern formation was 250 mJ/cm², indicating highsensitivity. Furthermore, when the pattern profile was observed byelectron microscopy, there was good 10 μm line and space resolution.

Example 4

[0096] Reaction was carried out up to prior to the action of theN,N-dimethylformamide dimethyl acetal using an identical composition tothat in Example 1, and polymerisation performed. Subsequently, 22.4 g(200 mmol) of potassium t-butoxide was added and stirring carried outfor 2 hours, after which 34.3 g (220 mmol) of ethyl iodide was addeddropwise. After two hours, the polymer solution was poured into purewater, so that the polymer precipitated, following which it was dried.The carboxyl group content in 1 g of this polymer was 1.2 mmol, thepercentage imidization was 20% and the absorbance at 365 nm was 0.088per 1 μm. 30 g of this polymer was dissolved in 70 g of GBL, and bydissolving 6 g of the quinone diazide compound 4NT-300 employed inExample 1 there was obtained the photosensitive resin compositionsolution.

[0097] Evaluation was carried out in the same way as in Example 1. Theresults are shown in Table 1. The film thickness of the unexposedregions following developing was 5.5 μm and so the film loss bydeveloping was 1.5 μM. Moreover, the light irradiation level at the timeof pattern formation was 300 mJ/cm², indicating high sensitivity.Furthermore, when the pattern profile was observed by electronmicroscopy, there was excellent 10 μm line and space resolution.

Example 5

[0098] An identical composition to that employed in Example 1, exceptthat there was used 29.45 g (200 mmol) of N-methyl-2-pyrrolidone diethylacetal instead of the N,N-dimethylformamide dimethyl acetal, was stirredfor 5 hours at 50° C. and a solution of partially esterified polymerobtained. The carboxyl group content in 1 g of this polymer was 0.28mmol, the percentage imidization was 8% and the absorbance at 365 nm was0.088 per 1 μm. A photosensitive solution was prepared in the same wayas in Example 1 using this polymer.

[0099] Evaluation was carried out in the same way as in Example 1. Theresults are shown in Table 1. The film thickness of the unexposedregions following developing was 5.5 μm and so the film loss due to thedeveloping was 1.5 μm. Moreover, the light irradiation level at the timeof pattern formation was 300 mJ/cam. Furthermore, when the patternprofile was observed by electron microscopy, there was good 5 μm lineand space resolution

Example 6

[0100] 13.6 g (36 mmol) of the hydroxyl group-containing diaminecompound (2) synthesized in Synthesis Example 3 and 0.99 g (4 mmol) of1,3-bis(3-aminopropyl)tetramethyldisiloxane were dissolved in 100 g ofNMP in a 1-litre four-necked flask under a current of dry nitrogen, then12.4.9 (40 mmol) of 3,3′,4,4′-diphenyl ether tetracarboxylic dianhydrideadded and stirring carried out for 3 hours at 80° C. Furthermore, 9.5 g(80 mmol) of N,N-dimethylformamide dimethyl acetal was added andstirring carried out for 2 hours at 50° C. Subsequently, 5 g (83 mmol)of acetic acid was added and the residual acetal compound decomposed. Asolution of partially esterified polymer was obtained. This polymersolution was poured into 5 litres of water, and the polymer precipitatecollected by filtration. This polymer was dried for 20 hours in a vacuumdrier at 80° C. The carboxyl group content of 1 g of this polymer was0.12 mmol, the percentage imidization was 12% and the absorbance at 365nm was 0.066 per 1 μm.

[0101] 10 g of this polymer and 2 g of the naphthoquinone diazidecompound synthesized in Synthesis Example 5 were mixed with 5 g of NMPand 25 g of GBL, and the photosensitive resin composition solutionobtained.

[0102] Evaluation was carried out in the same way as in Example 1 exceptthat the developing time was 70 seconds. The results are shown inTable 1. The film thickness of the unexposed regions followingdeveloping was 5.5 μm and so the film loss due to the developing was 1.5μm. Moreover, the light irradiation level at the time of patternformation was 250 mJ/cm². Furthermore, when the pattern profile wasobserved by electron microscopy, there was good 10 μm line resolution.

Example 7

[0103] 8.75 g (36 mmol) of the hydroxyl group-containing diaminecompound (3) synthesized in Synthesis Example 2 and 0.99 g (4 mmol) of1,3-bis(3-aminopropyl)tetramethyldisiloxane were dissolved in 100 g ofNMP in a 1-litre four-necked flask under a current of dry nitrogen, then12.9 g (40 mmol) of 3,3′,4,4′-benzophenonetetracarboxylic dianhydrideadded and stirring carried out for 3 hours at 50° C. Furthermore, 10.7 g(90 mmol) of N,N-dimethylformamide dimethyl acetal was added andstirring carried out for 2 hours at 50° C. A solution of partiallyesterified polymer was obtained. The carboxyl group content of 1 g ofthis polymer was 0.08 mmol, the percentage imidization was 11% and theabsorbance at 365 nm was 0.086 per 1 μm.

[0104] 100 g of this polymer solution was mixed with 3.5 g of thequinone diazide compound 4NT-300 employed in Example 1 and thephotosensitive resin composition solution obtained.

[0105] Evaluation was carried out in the same way as in Example 1 exceptthat the developing time was 90 seconds. The results are shown inTable 1. The film thickness of the unexposed regions followingdeveloping was 5.8 μm and so the film loss due to the developing waslow, at 1.2 μm. Moreover, the light irradiation level at the time ofpattern formation was 450 mJ/cm²Furthermore, when the pattern profilewas observed by electron microscopy, there was good 10 μm lineresolution.

Comparative Example 1

[0106] A photosensitive resin precursor solution was obtained in thesame way as in Example 1 except that no N,N-dimethyl formamide dimethylacetal was added. The carboxyl group content of the polymer was 2.3mmol, the percentage imidization was 7% and the absorbance at 365 nm was0.083 per 1 μm.

[0107] Evaluation was carried out in the same way as in Example 1, butall the film dissolved.

Comparative Example 2

[0108] 50 g of pyromellitic dianhydride and 300 ml of ethanol wereintroduced into a 500 ml flask, and 0.2 ml of pyridine added andstirring carried out for 10 hours at 30° C. under a nitrogen atmosphere.The excess ethanol was distilled off under reduced pressure and bydrying the residue under vacuum the diethyl ester of pyromellitic acidwas obtained.

[0109] 31.4 g (100 mmol) of the diethyl ester of pyromellitic acid thusobtained and 100 ml of thionyl chloride were introduced into a flask andstirred for 1 hour at room temperature, after which refluxing wasperformed for 3 hours. The excess thionyl chloride was eliminated bymeans of an aspirator and the acid chloride obtained.

[0110] The acid chloride obtained was dissolved in 60 g of GBL and addeddropwise to a solution of 36.62 g (100 mmol) of BAHF and 50 ml ofpyridine dissolved in 200 ml of NMP, with said solution being maintainedat 0° C. After continuing to stir for 3 hours at 0° C., stirring wascarried out for a further 3 hours at 30° C. The insoluble material wasthen filtered off, following which the filtrate was poured Into 5 litresof water and the polymer precipitated. The carboxyl group content of 1 gof this polymer was 0 mmol, the percentage imidization was 4% and theabsorbance at 365 nm was 0.072 per 1 μm. Furthermore, the residualchlorine ion concentration of this polymer was high, at 100 ppm, whichis a problem in terms of its use in semiconductor applications. Theresidual sodium, potassium and iron ions were all no more than 10 ppm.

[0111] 20 g of the polyamic acid diethyl ester obtained was dissolved in60 g of GBL, and by dissolving 5 g of the quinone diazide compound4NT-300 used in Example 1, the photosensitive resin composition solutionwas obtained.

[0112] Evaluation was carried out in the same way as in Example 1, buteven when immersed for over 5 minutes in the developer liquid theexposed regions did not completely dissolve. The film thickness of theregion exposed at 500 mJ/cmm2 was 5.1 μm and the film thickness of theunexposed regions remained the same at 7 μm.

Comparative Example 3

[0113] A photosensitive resin precursor solution was obtained in thesame way as in Example 1 except that the polymerisation and theesterification reaction were carried out at 180° C. The carboxyl groupcontent of 1 g of this polymer was 0.01 mmol, the percentage imidizationwas 65% and the absorbance at 365 nm was 0.153 per 1 μm.

[0114] Evaluation was carried out in the same way as in Example 1. As aresult, the film thickness of the unexposed regions following developingwas 5.5 μm and so the film loss due to the developing was 1.5 μm, butthe light irradiation level required at the time of pattern formationwas at least 750 mJ/cm², so the sensitivity was extremely poor.

Example 8

[0115] 20.0 g (100 mmol) of 4,4′-diaminodiphenyl ether was dissolved in350 g of NMP in a 1-litre four-necked flask under a current of drynitrogen. To this, 71.4 g (100 mmol) of the acid anhydride synthesizedin Synthesis Example 1 was added along with 40 g of GBL, and reactioncarried out for 1 hour at 20° C. followed by 4 hours at 50° C. Aftercooling to 20° C., 24.0 g (240 mmol) of tert-butyl vinyl ether was addedand stirring carried out for 24 hours at 20° C. A solution of partiallyesterified polymer was obtained. The carboxyl group content of 1 g ofthis polymer was 0.38 mmol, the percentage imidization was 20% and theabsorbance at 365 nm was 0.084 per 1 μm.

[0116] 5.5 g of 4NT-300 was added to 100 g of the solution obtained andthe photosensitive resin composition solution obtained.

[0117] Evaluation was carried out in the same way as in Example 1 exceptthat the developing time was 60 seconds. As a result, the film thicknessof the unexposed regions following developing was 5.6 μm and so the filmloss due to the developing was low, at 1.4 γm. Furthermore, the minimumlight irradiation level at the time of pattern formation was low, at 350mJ/cm², so the sensitivity was good. Moreover, when the pattern profilewas observed by means of an electron microscope, there was good 10 μmline and space resolution.

Example 9

[0118] 24.2 g (40 mmol) of the diamine compound synthesized in SynthesisExample 2 was dissolved in 100 g of NMP in a 1-litre four necked flaskunder a current of dry nitrogen, then 11.8 g (40 mmol) of3,3′,4,4′-biphenyltetracarboxylic dianhydride added and stirring carriedout for 3 hours at 80° C. Furthermore, 9.2 g (72 mmol) of cyclohexylvinyl ether was added and stirring carried out for 24 hours at 20° C. Asolution of partially esterified polymer was obtained. The carboxylgroup content of 1 g of this polymer was 0.40 mmol, the percentageimidization was 36% and the absorbance at 365 nm was 0.065 per 1 μm.Furthermore, the residual sodium, potassium and iron concentrations inthis polymer were good values of no more than 10 ppm. Again, theresidual chlorine concentration was a good value of no more than 10 ppm.

[0119] 100 g of this polymer solution and 3.5 g of the quinone diazidecompound 4NT-300 employed in Example 1 were mixed together and thephotosensitive resin composition solution obtained.

[0120] Evaluation was carried out in the same way as in Example 1 exceptthat the developing time was 50 seconds. As a result, the film thicknessof the unexposed regions following developing was 5.7 μm and so the filmloss due to the developing was low, at 1.3 μm. Furthermore, the lightirradiation level at the time of pattern formation was 400 mJ/cm².Moreover, when the pattern profile was observed by means of an electronmicroscope, there was good 10 μm line resolution.

Example 10

[0121] Polymerization was carried out in the same way as in Example 1except that the diamine composition was 18.3 g (50 mmol) of2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (BAHF), 8.0 g (40mmol) of 4,4′-diaminodiphenyl ether and 2.5 g (10 mmol) of1,3-bis(3-aminopropyl)tetramethyldisiloxane. The carboxyl group contentof 1 g of this polymer was 0.21 mmol, the percentage imidization was 20%and the absorbance at 365 nm was 0.056 per 1 μm. 30 g of this polymerwas dissolved in 70 g of GBL, and by dissolving 6 g of the quinonediazide compound 4NT-300 employed in Example 1 there was obtained thephotosensitive resin composition solution.

[0122] Evaluation was carried out in the same way as in Example 1As aresult, the film thickness of the unexposed regions following developingwas 6.0 μm and so the film loss due to developing was low, at 1.0 μm.Furthermore, the value of the light irradiation level at the time ofpattern formation was 350 mJ/cm², so there was high sensitivity.Moreover, when the pattern profile was observed by means of an electronmicroscope, there was excellent 10 μm line and space resolution.

Example 11

[0123] Using a composition identical to that in Example 1, reaction wascarried out up to prior to the action of the N,N-dimethylformamidedimethyl acetal, and polymer produced. Subsequently, after cooling to0.20° C., 24.0 g (240 mmol) of tert-butyl vinyl ether was added and 0.72g (5.52 mmol) of phosphoric acid added dropwise After stirring for 24hours at 20° C., the polymer solution was poured into pure water and thepolymer precipitated, following which it was dried for 24 hours in avacuum drier at 80° C. The carboxyl group content of 1 g of this polymerwas 0.08 mmol, the percentage imidization was 10% and the absorbance at365 nm was 0.042 per 1 μm. 30 g of this polymer was dissolved in 70 g ofGBL, and by dissolving 6 g of the quinone diazide compound 4NT-300employed in Example 1, there was obtained the photosensitive resincomposition solution.

[0124] Evaluation was carried out in the same way as in Example 1. As aresult, the film thickness of the unexposed regions following developingwas 6.4 μm and so the film loss due to the developing was low, at 0.6μm. Furthermore, the light irradiation level at the time of patternformation was 250 mJ/cm², so there was high sensitivity. Moreover, whenthe pattern profile was observed by means of an electron microscope,there was excellent 5 μm line and space resolution.

Example 12

[0125] With a composition identical to that in Example 1, reaction wascarried out up to prior to the action of the N,N-dimethylformamidedimethyl acetal, and polymer produced.

[0126] Subsequently, 20.9 g (240 mmol) of isopropyl vinyl ether wasadded and then 0.72 g (5.52 mmol) of phosphoric acid added dropwise.Stirring was carried out for 20 hours at 25° C., and a solution ofpartially esterified polymer obtained. The carboxyl group content of 1 gof this polymer was 0.12 mmol, the percentage imidization was 12% andthe absorbance at 365 nm was 0.083 per 1 μm.

[0127] Evaluation was carried out in the same way as in Example 1. As aresult, the film thickness of the unexposed regions following developingwas 6.2 μm and so the film loss due to the developing was low, at 0.8μm. Furthermore, the light irradiation level at the time of patternformation was 300 mJ/cm². Moreover, when the pattern profile wasobserved by means of an electron microscope, there was good 5 μm lineand space resolution.

Example 13

[0128] 18.9 g (50 mmol) of the hydroxyl group-containing diamine (2)synthesized in Synthesis Example 3, 16.5 g (45 mmol) of BAHF and 1.24 g(5 mmol) of the 1,3-bis(3-aminopropyl)tetramethyldisiloxane weredissolved in 250 g of NMP and adjusted to 30° C. To this solution, therewas added 31.0 g (100 mmol) of 3,3′,4,4′-diphenyl ether tetracarboxylicdianhydride together with 50 g of NMP, and stirring carried out for 1hour at 30° C. and then for 2 hours at 50° C. Subsequently, with thesolution temperature maintained at 50° C., there was added a solution of23.8 g (200 mmol) of N,N-dimethylformamide dimethyl acetal diluted with80 g of NMP, and the stirring continued for two hours at 50° C.Thereafter, the temperature of the solution was adjusted to 30° C., and60 g (1 mol) of acetic acid added along with 80 g of NMP. Stirring wascarried out for 1 hour at ₃₀° C. and the excess acetal compounddecomposed. Following the end of the reaction, the polymer solution waspoured into 10 litres of water and a precipitate of the polymerobtained. This was collected by filtering and dried for 24 hours in aventilated oven at 80° C. The residual sodium, potassium and iron ionconcentrations in the polymer were good, at no more than 10 ppm.Furthermore, the residual chlorine concentration was also good, at nomore than 10 ppm.

[0129] The carboxyl group content of 1 g of this polymer was 0.43 mmol,the percentage imidization was 11% and the absorbance at 365 nm was0.075 per 1 μm. 10 g of this polymer was dissolved in 70 g of NMP, andby dissolving 2 g of a sensitising agent (MG-300, produced by the ToyoGosei Co.) formed by the reaction of 3 mol of 5-naphthoquinonediazidesulphonyl chloride with 1 mol of methyl gallate, there was obtained aphotosensitive resin composition solution.

[0130] Evaluation was carried out in the same way as in Example 1 exceptthat the developing time was 70 seconds. The results are shown inTable 1. As a result, the film thickness of the unexposed regionsfollowing developing was 5.8 μm and so the film loss due to thedeveloping was low, at 1.2 μm. Furthermore, the light irradiation levelat the time of pattern formation was 350 mJ/cm², so the sensitivity washigh. Moreover, when the pattern profile was observed by means of anelectron microscope, there was good 10 μm line and space resolution.

Example 14

[0131] 12.2 g (50 mmol) of the hydroxyl group-containing diamine (3)synthesized in Synthesis Example 4, 16.5 g (45 mmol) of BAHF and 1.24 g(5 mmol) of 1,3-bis(3-aminopropyl)tetramethyldisiloxane were dissolvedin 180 g of NMP, and the solution adjusted to 30° C. To this solution,31.0 g (100 mmol) of 3,3′,4,4′-diphenyl ether tetracarboxylicdianhydride was added along with 50 g of NMP, and stirring carried outfor 1 hour at 30° C. and then for 2 hours at 50° C. Subsequently, withthe solution temperature held at 50° C., a solution of 23.8 g (200 mmol)of N,N-dimethylformamide dimethyl acetal dissolved in 80 g of NMP wasadded and stirring continued for 2 hours at 50° C. Subsequently, thesolution temperature was lowered to 30° C., 24 g (400 mmol) of aceticacid together with 30 g of NMP added, and stirring carried out for 1hour at 30° C., so that the excess acetal compound was decomposed.Following the end of the reaction, the polymer solution was poured into10 litres of water and a precipitate of polymer obtained. This wascollected by filtering and drying carried out for 24 hours in aventilated oven at 80° C. The residual sodium, potassium and ironconcentrations of this polymer were good values of no more than 10 ppm.Moreover, the residual chlorine concentration was also good, at no morethan 10 ppm.

[0132] The carboxyl group content of 1 g of this polymer was 0.44 mmol,the percentage imidization was 11% and the absorbance at 365 nm was0.055 per 1 μm. 30 g of this polymer was dissolved in 70 g of NMP, andby dissolving 6 g of the naphthoquinone diazide compound MG-300, therewas obtained the photosensitive resin composition solution.

[0133] Evaluation was carried out in the same way as in Example 1 exceptthat the developing time was 60 seconds. The results are shown InTable 1. As a result, the film thickness of the unexposed regionsfollowing developing was 6.0 μm and so the film loss due to thedeveloping was low, at 1.0 μm. Furthermore, the light irradiation levelat the time of pattern formation was 350 mJ/cm², so the sensitivity washigh. Moreover, when the pattern profile was observed by means of anelectron microscope, there was good 10 μm line and space resolution.

Examples 15 to 17

[0134] 57.4 g (95 mmol) of the hydroxyl group-containing diamine (1)synthesized in Synthesis Example 2 and 1.24 g (5 mmol) of1.3-bis(3-aminopropyl)tetramethyldisiloxane were dissolved in 180 g ofNMP and the solution adjusted to 30° C. To this, there was added 31.0 g(100 mmol) of 3,3′,4,4′diphenyl ether tetracarboxylic dianhydridetogether with 30 g of NMP, and stirring carried out for 1 hour at 30° C.followed by 2 hours at 50° C. Subsequently, with the solutiontemperature maintained at 50° C., the specified amount of N,N-dimethylformamide dimethyl acetal shown below was added along with 100g of NMP (Example 15: 20.2 g (170 mmol), Example 16: 22.6 g (190 mmol)and Example 17: 25.0 g (210 mmol)). Thereafter, stirring was continuedfor 2 hours at 50° C. Subsequently, the temperature of the solution wasmade 30° C., 24 g (400 mmol) of acetic acid added and stirring carriedout for 1 hour at 30° C., to decompose the excess acetal compound.Following the end of the reaction, the polymer solution was poured into10 litres of water and a precipitate of polymer obtained. This wascollected by filtering and dried for 24 hours in a ventilated oven at80° C. The residual sodium, potassium and iron concentrations of thepolymer obtained in each case were good values of no more than 10 ppm.Furthermore, the residual chlorine concentration was also good, at nomore than 10 ppm.

[0135] In Example 15, the carboxyl group content of 1 g of the polymerwas 0.60 mmol, the percentage imidization was 9% and the absorbance at365 nm was 0.044 per 1 μm; in Example 16 the carboxyl group content of 1g of the polymer was 0.47 mmol, the percentage imidization was 9% andthe absorbance at 365 nm was 0.044 per 1 μm: and in Example 17 thecarboxyl group content of 1 g of the polymer was 0.41 mmol, thepercentage imidization was 11% and the absorbance at 365 nm was 0.045per 1 μm. 30 g quantities of these polymer were respectively dissolvedin 35 g of GBL and 35 g of NMP, and by dissolving 6 g of thenaphthoquinone diazide compound synthesized in Synthesis Example 5,there were obtained photosensitive resin composition solutions.

[0136] Evaluation was carried out in the same way as in Example 1 exceptthat the developing time was made 50 seconds (Example 15), 70 seconds(Example 16) or 90 seconds (Example 17). The results are shown inTable 1. In each case, the film loss due to the developing was good, atno more than 1.2 μm. Furthermore, the light irradiation level at thetime of pattern formation was from 250 mJ/cm² to 300 mJ/cm², so thesensitivity was high. Moreover, when the pattern profile was observed bymeans of an electron microscope, there was excellent 5 μm line and spaceresolution.

INDUSTRIAL APPLICATION POTENTIAL

[0137] In accordance with the present invention it is possible to adjustthe dissolution rate in terms of aqueous alkali solution and, moreover,it is possible to obtain a photosensitive resin composition of hightransparency at the exposure wavelength and high sensitivity. TABLE 1Photosensitive Resin Composition Properties Composition MinimumComponent Esterifying Esterification Carboxyl Percentage IrradiationReso- R1 Component R2 Agent (mol Reaction Groups Imidization Absor-Remaining Level lution (mol ratio) (mol ratio) ratio) Conditions, etc(mmol/g) (%) bance Film (%) (mJ/cm²) (μm) Exam- Synthesis DDE (100)DMFDMA 50° C. 5 hours 0.07 10 0.083 80 300 5 ple 1 Example (200) 1 (100)Exam- BPDA (100) Synthesis Example DMFDEA (150) 80° C. 3 hours 0.55 350.066 83 250 10 ple 2 2 (100) Exam- Synthesis BAHF/DDE/SiDA DMFDMA 50°C. 5 hours 0.35 14 0.045 86 250 10 ple 3 Example (50/40/10) (200) 1(100)Exam- Synthesis DDE (100) t-BuOK (200) 30° C. 1.2 20 0.088 79 300 10 ple4 Example 1(100) Exam- Synthesis DDE (100) NMPDMA 50° C. 5 hours 0.28 80.082 79 300 5 ple 5 Example (200) 1(100) Exam- DEDA (100) SynthesisExample DMFDEA (200) 80° C. 3 hours 0.12 12 0.066 79 250 10 ple 6 3/SiDA(90/10) Exam- BTDA (100) Synthesis Example DMFDEA (225) 50° C. 2 hours0.08 11 0.066 83 450 10 ple 7 2/SiDA (90/10) Exam- Synthesis DDE (100)TBVA (240) 20° C. 24 hours 0.18 20 0.084 80 350 10 ple 8 Example 1(100)Exam- BPDA (100) Synthesis Example CHVE (180) 20° C. 24 hours 0.40 360.065 81 400 5 ple 9 2 (100) Exam- Synthesis BAHF/DDE/SiDA DMFDMA 50° C.5 hours 0.21 20 0.056 86 350 10 ple 10 Example (50/40/10) (200) 1(100)Exam- Synthesis DDE (100) TBVA (240) 20° C. 24 hours 0.08 10 0.042 93250 5 ple 11 Example 1(100) Exam- Synthesis DDE (100) JPVE (240) 25° C.20 hours 0.12 12 0.083 81 300 5 ple 12 Example 1(100) Exam- DEDA (100)Synthesis Example DMFDEA (200) 50° C. 2 hours 0.43 11 0.075 83 350 10ple 13 3/BAHF/SiDA (50/45/5) Exam- DEDA (100) Synthesis Example DMFDEA(200) 50° C. 21 hours 0.44 11 0.055 86 350 10 ple 14 4/BAHF/SiDA(50/45/5) Exam- DEDA (100) Synthesis Example DMFDMA 50° C. 2 hours 0.609 0.044 86 250 5 ple 15 2/SiDA (95/5) (170) Exam- DEDA (100) SynthesisExample DMFDMA 50° C. 2 hours 0.47 8 0.044 86 250 5 ple 16 2/SiDA (95/5)(190) Exam- DEDA (100) Synthesis Example DMFDMA 50° C. 2 hours 0.41 100.045 90 300 5 ple 17 2/SiDA (95/5) (210) Comp. Synthesis DDE (100) nonenone 2.3 7 0.083 all — — Ex. 1 Example dissolves 1 (100) Comp. PMDA(100) BAHF (100) ethanol (large 30° C. 10 hours 0 4 0.072 insoluble — —Ex. 2 excess) Comp. Synthesis DDE (100) DMFDMA 180° C. 5 hours 0.01 6.50.113 79 750 10 Ex. 3 Example (200) 1(100)

1. A positive-working photosensitive resin precursor composition whichis characterized in that it contains (a) polymer in which structuralunits of the kind denoted by general formula (1) are the chief componentand (b) photoacid generator, and the total carboxyl groups contained insaid polymer is from 0.02 to 2.0 mmol/g.

(R¹ is an organic group of valency from 3 to 8 having at least 2 carbonatoms, R² is an organic group of valency from 2 to 6 having at least 2carbon atoms, R³ is hydrogen or a monovalent organic group with from 1to 10 carbons but it is not all hydrogen nor is it all a monovalentorganic group with from 1 to 10 carbons. n is an integer of value from 3to 100,000, m is 1 or 2, p and q are integers of value from 0 to 4 andp+q>0.)
 2. A positive-working photosensitive resin precursor compositionaccording to claim 1 which is characterized in that the photoacidgenerator is a quinone diazide compound.
 3. A positive-workingphotosensitive resin composition according to claim 1 which ischaracterized in that some of the carboxyl groups of the polymerrepresented by general formula (1) are imidized by reaction with anadjacent amide group, and the percentage such imidization is from 1% to50%.
 4. A positive-working photosensitive resin composition according toclaim 1 which is characterized in that the absorbance of the polymerrepresented by general formula (1) at 365 nm is no more than 0.1 per 1μm of film thickness.
 5. A positive-working photosensitive resinprecursor composition according to claim 1 which is characterized inthat R¹(COOR³)_(m)(OH)_(p) in general formula (1) is represented by thefollowing general formula (6).

(R⁷ and R⁹ represent C₂ to C₂₀ organic groups of valency 3 or 4, R⁸represents a hydroxyl group-containing C₃ to C₂₀ organic group ofvalency from 3 to 6, and R¹⁰ and R¹¹ each represent hydrogen or a C₁ toC₁₀ monovalent organic group. R¹⁰ and R¹¹ are not all hydrogen atoms,nor are they all C₁ to C₁₀ monovalent organic group. r and t representthe integers 1 or 2, and s denotes an integer of value from 1 to 4.) 6.A positive-working photosensitive resin precursor composition accordingto claim 1 which is characterized in that R²(OH)_(q) in general formula(1) is represented by the following general formula (7).

(R¹² and R¹⁴ represent hydroxyl group-containing C₂ to C₂₀ organicgroups of valency 3 or 4, and R¹³ represents a C₂ to C₃₀ divalentorganic group. u and v represent the integer 1 or 2.)
 7. Apositive-working photosensitive resin precursor composition according toclaim 7 which is characterized in that R²(OH)_(q) in general formula (1)is represented by the following general formula (8).

(R¹⁵ and R¹⁷ represent C₂ to C₃₀ divalent organic groups, and R¹⁶represents a hydroxyl group-containing C₂ to C₂₀ organic group ofvalency from 3 to
 6. w represents an integer in the range from 1 to 4.)8. A positive-working photosensitive resin precursor compositionaccording to claim 1 which is characterized in that R²(OH)_(q) ingeneral formula (1) is represented by general formula (9).

(R¹⁶ represents a C₂ to C₃₀ divalent organic group, and R¹⁹ represents ahydroxyl group-containing C₂ to C₂₀ organic group of valency from 3 to6. x represents an integer in the range from 1 to 4.)
 9. Apositive-working photosensitive resin precursor composition according toclaim 1 which is characterized in that, in the polymer represented bygeneral formula (1), at least 50% of R¹(COOR³)_(m)(OH)_(p) are groupsrepresented by general formula (6), and the group represented by R² is adivalent diamine compound residual group which does not contain ahydroxyl group.
 10. A positive-working photosensitive resin precursorcomposition according to claim 1 which is characterized in that, ingeneral formula (1), at least 50% of R²(OH)_(q) is a group representedby general formula (7), and the group represented by R¹ is atetracarboxylic acid residual group.
 11. A positive-workingphotosensitive resin precursor composition according to claim 1 which ischaracterized in that, in general formula (1), at least 50% ofR²(OH)_(q) is a group represented by general formula (8), and the grouprepresented by R¹ is a tetracarboxylic acid residual group.
 12. Apositive-working photosensitive resin precursor composition according toclaim 1 which is characterized in that, in general formula (1), at least50% of R²(OH)_(q) is a group represented by general formula (9), and thegroup represented by R¹ is a tetracarboxylic acid residual group.
 13. Amethod of producing a positive-working photosensitive resin precursorcomposition according to claim 1 which is characterized in that thecompound represented by general formula (1) is produced by treatingpolymer in which structural units represented by general formula (2) arethe chief component with at least one type of compound represented bygeneral formulae (3), (4) or (5).

(R¹ is an organic group of valency from 3 to 8 having at least 2 carbonatoms, and R² is an organic group of valency from 2 to 6 having at least2 carbon atoms. n is an integer of value from 3 to 100,000, m is 1 or 2,p and q are integers of value from 0 to 4 and p+q>0.)

(R⁴ and R⁵ represent a hydrogen atom or a monovalent organic group,nitrogen-containing organic group or oxygen-containing organic groupwith at least one carbon atom. R6 represents a monovalent organic groupwith at least one carbon. R⁷ represents a divalent organic group,nitrogen-containing group or oxygen-containing organic group with atleast one carbon atom.) 14 A method of producing a positive-workingphotosensitive resin precursor composition according to claim 13 whichis characterized in that the compound represented by general formula (3)is an N,N-dimethylformamide dialkyl acetal.
 15. A method of producing apositive-working photosensitive resin precursor composition according toclaim 13 which is characterized in that the compound represented bygeneral formula (5) is cyclohexyl vinyl ether.